Combining Electrochemiluminescence Detection with Aptamer-Gated Indicator Releasing Mesoporous Nanoparticles Enables ppt Sensitivity for Strip-Based Rapid Tests

Angew Chem Int Ed Engl. 2021 Dec 6;60(50):26287-26297. doi: 10.1002/anie.202110744. Epub 2021 Nov 9.

Abstract

The combination of electrogenerated chemiluminescence (ECL) and aptamer-gated indicator delivering (gAID) magnetic mesoporous silica nanoparticles embedded into glass fibre paper functionalised with poly(ethyleneglycol) and N-(3-triethoxysilylpropyl)diethanolamine allowed the development of a rapid test that detects penicillin directly in diluted milk down to 50±9 ppt in <5 min. Covalent attachment of the aptamer "cap" to the silica scaffold enabled pore closure through non-covalent electrostatic interactions with surface amino groups, while binding of penicillin led to a folding-up of the aptamer thus releasing the ECL reporter Ru(bpy)32+ previously loaded into the material and letting it be detected after lateral flow by a smartphone camera upon electrochemical excitation with a screen printed electrode inserted into a 3D-printed holder. The approach is simple, generic and presents advantages with respect to sensitivity, measurement uncertainty and robustness compared with conventional fluorescence or electrochemical detection, especially for point-of-need analyses of challenging matrices and analytes at ultra-trace levels.

Keywords: electrochemiluminiscence; hybrid materials; penicillin; signal amplification; test strip analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aptamers, Nucleotide / chemistry*
  • Electrochemical Techniques*
  • Indicators and Reagents / chemistry*
  • Luminescent Measurements*
  • Nanoparticles / chemistry
  • Particle Size
  • Penicillins / analysis*
  • Porosity
  • Reagent Strips / chemistry*
  • Surface Properties

Substances

  • Aptamers, Nucleotide
  • Indicators and Reagents
  • Penicillins
  • Reagent Strips